Sovereignty itself is, of course, not subject to law, for it is the author and source of law; but in our system, while sovereign powers are delegated to the agencies of government, sovereignty itself remains with the people, by whom and for whom all government exists and acts.Yick Wo v. Hopkins, 118 U.S. 356 (1886)

But these Indians are within the geographical limits of the United States. The soil and the people within these limits are under the political control of the government of the United States , or of the states of the Union . There exists within the broad domain of sovereignty but these two. There may be cities, counties, and other organized bodies, with limited legislative functions, but they are all derived from, or exist in, subordination to one or the other of these.US v. KAGAMA, 118 U.S. 375 (1886)

With the debate centering on which governments are sovereign, almost no attention has been given to the derivation of tribal authority and the basis of its sovereignty vis-à-vis individual tribal members… Nearly all the Plains Indians lived in relatively independent groups (usually families or clans) where individual freedom was paramount… Before Indian tribes, especially those with a tradition of individualism, can establish their sovereignty, they must establish the nature of the relationship between individual Indians and tribal government…To develop collective sovereignty, Indians will have to return to the basics of individual sovereignty and build from the ground up…Self-determination begins with the individual, as it did prior to European contact, and builds to collective action
Anderson, Terry L. Sovereign Nations or Reservations, (San Francisco: Pacific Research Institute, 1995) p. 169-171. Reprinted with permission of the Pacific Research Institute for Public Policy.